DRAPER, JoiIN \Vitu.km ( I SI I-Se). American chemist, physiologist, and philosophi cal writer. lie was born near Liverpool. Eng land. and was educated at a \\e-It-van school at \Voodhouse (;rove, and at London University. In l$31 he joined some of his relatives who had emigrated to .‘nierii.a. and in I836 took his degree of doctor of medicine in the University of Pennsylvania and was appointed professor of natural philosophy. elleinktry, and physiology in Ilanipden-Sidney C'ollege, Virginia. In IS:to he removed to New York, where he was (.on fleeted with the college department of the University of the City of New York; and in lS41 joined Drs. Mott, Patterson. and others in founding the medical school of New York Uni versity, in which he was at lirst professor of after I s51) of physiology. lie published a Tr,atise on Ho l'o•c•s trhich Pro due, ttryani:ation in Plants (Is 11 : n.0-flat& of chemistry ( IS 41;) ; a Ti .rt -Book if fit lira I Ph ilosoph y ( Is471: and Human Statical and or, the Conditions and Course of Li f of ilea.
Dr. Draper's lasting contributions to physi ology and to pure chemistry were few and rela tively unimportant. ttri the other hand. his name is associated with a number of results of the greatest value in physical chemistry, especially in photochemistry (9.v.).. The chem ical action of light early attracted his attention and for many }car- formed his fa orite subject of investigation, lie succeeded in demonstrat ing that different colors of light have an unequal influence on the decomposition of car bonic acid by the green pigment of plants. The spectra of Iiight entitled by incandescent sub stance- engaged his attention a. a, Ist7, and his memoirs show that at that early date he had already grasped the wonderfill possibili ties of spectrum analysis in both and astrcmotny, lie further succeeded in show that all part- of the spectrum. the in\ isible as well a, the visible ones, are capable if chemical action. in the art of p1gtog
)aphy entitle hint to an eminent place atiumg the great. in\ entor- if the nineteenth century. The principle of photography was established by the hreuchnanr Daguerrc: but anti practically incapable if u-e fin application. It was 1/raper's improvements that rendered it po,,ible to apply photography to the representation of the human countenanc•, and the first photograph taken by Draper in 1S39. in the old building of the New York University. .\ valuable collection of Draper': pub was published in Isis, under the title, Scien/ific .1Ltinrir.s. Bei l:.1 men ill Con t ribut ions to a K noirleilyi of Ntoliant Ette•yY.
a It-miter 44 science and a prolifie \vriter on scientific subject-. !)raper will, perhaps, best be remembered a, the anther of works %%bleb more properly belong to the domain of philo-ophiiial Iii-tory. The first of these and the no-t import:int 7'/1e Ilistory of thr Intellectual It( r,loionent of 1:nroin. (2 vols., 18;31, in which he to the method.; of science to Inman hi-tory, and to prove in ductively that advancement is as entil plote1y under the control of natural law as is :\litelt of his data, both scientific and historical. lias been superseded, and some of his conclusions are discredited. lint the work is charaeterized by tion-ideralile i•ruilition and a clearness of presentation. and is -till much read. Ilistory of the .1 meriran Thar (3 vols.. ISIl7-701. though it give, a graphic and fairly accurate account of the military operations, is chiefly valuable for it- elaborate analysis of the eau-es, immediate and remote, which made a war bet \\Ten the North and the South inevitable. The most popular of his \v,irks, is his iiisto•y if tirc Confilet 1,'cliaion and arc I New York. I874 a candid. philosophical. and fairly comprehensive treatment of t he -object. Ban'ker's in ii. of the Mon•/pi/fen/ ..1/(moirs of :be \ tr I .1c(olcin y of Nrienre.